Since a research team of Michael Gratzel at the Ecole Polytechnique Federale de Lausanne (EPFL) in Switzerland developed a dye-sensitive nano particle titanium dioxide solar cell in 1991, lots of studies have been conducted on the area. The dye-sensitized solar cell requires significantly lower manufacturing costs than an existing silicon solar cell does, and can possibly replace an existing amorphous silicon solar cell. Unlike a silicon solar cell, the dye-sensitized solar cell is a photoelectrochemical solar cell which includes a dye molecule absorbing visible rays to generate an electron-hole pair and a transition metal oxide transferring a generated electron, as main materials.
Representative dyes which are used in a conventional dye-sensitized solar cell may include following compounds.

The foregoing conventional dyes are called N820 and N945, respectively.
If the conventional dyes are used to manufacture a solar cell, a 15 μm to 20 μm oxide semiconductor particle layer should be provided to apply the dyes thereto. However, the dye and the oxide semiconductor particles are very expensive and account for 30% or more manufacturing costs of the dye-sensitized solar cell. Thus, there have been consistent requests to develop a dye providing higher photoelectric conversion efficiency while the usage amount of the dyes and the oxide semiconductor particles is reduced. With the request for a thinner solar cell continued, studies on proper materials are being conducted.